// --------------------------------------------------------------------------------------------------------------------
// <copyright file="IAgentHost.cs" company="Microsoft Corporation">
// The MIT License (MIT)
// 
// Copyright (c) 2014, Microsoft Corporation
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
//  of this software and associated documentation files (the "Software"), to deal
//  in the Software without restriction, including without limitation the rights
//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//  copies of the Software, and to permit persons to whom the Software is
//  furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
//  all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
//  THE SOFTWARE.
// </copyright>
// --------------------------------------------------------------------------------------------------------------------
namespace Microsoft.Robotics.Runtime
{
    using System;

    /// <summary>
    /// This is the public part of AgentHost. This is what agents get when they ask the Locator for a partner agent.
    /// </summary>
    public interface IAgentHost
    {
        /// <summary>
        /// Gets a value indicating whether the agent is active (i.e. was activated at least once), false otherwise. 
        /// </summary>
        bool IsActive { get; }

        /// <summary>
        /// Called to "activate" an agent. 
        /// </summary>
        void Activate();

        /// <summary>
        /// Called when the agent is no longer required by one of its partners. 
        /// Each call to Deactivate is paired with a prior call to Activate.
        /// </summary>
        void Deactivate();

        /// <summary>
        /// Retrieves a control message forwarder for the given message type.
        /// </summary>
        /// <typeparam name="TMessage">The type of control message.</typeparam>
        /// <returns>A forwarder that can be used to submit control messages of the specified type to the wrapped agent.</returns>
        IForwarder<TMessage> GetControlPort<TMessage>() where TMessage : AgentMessage;

        /// <summary>
        /// Subscribes a consumer to the wrapped agent. The subscriber will start receiving messages once this agent is activated.
        /// </summary>
        /// <typeparam name="TMessage">The type of input messages to receive.</typeparam>
        /// <param name="consumerProducerAgent">The friendly name of the agent to subscribe to.</param>
        void Subscribe<TMessage>(ISubscriptionReceiver<TMessage> consumerProducerAgent) where TMessage : AgentMessage;

        /// <summary>
        /// Subscribes a consumer to the wrapped agent. The subscriber will start receiving messages once this agent is activated.
        /// </summary>
        /// <param name="messageType">The type of input messages to receive.</param>
        /// <param name="consumerProducerAgent">The friendly name of the agent to subscribe to.</param>
        void Subscribe(Type messageType, ISubscriptionReceiver consumerProducerAgent);
    }
}
